Could you please help me to resolve my problem?

Let us consider A=[a,-b,c, d, -a,b, -d]. Is there any command or function to remove negative element from A? For this example I want to obtain [a,b,c,d]. It is worth noting that not different "a" belong in the output list or "-a".

Thank you in advance.

Dear all

I would like to obtain an equivalent to this integral when n goes to infinity 

int( ((1-t^2)^n, t=0..1)

Many thanks

download the file

Download ask.mw 

Let's consider nonlinear partial differential equations as follows:

It can be reduced into the nonlinear ordinary differential equation

by using the transformation as follows:

How to write a code for transforming the PDE to ODE by Maple?
 

For example; let's consider the following PDE

by using the transformation above we get the following ODE. 

restart:
with(PDEtools):
tr1:={x=mu*t + xi,u(x,t)=U(xi) };
PDE := diff(u(x,t),t) +p*u(x,t)*diff(u(x,t),x) +q* diff(u(x,t),x$3)=0;
dchange(tr1,PDE);

How I can obtain system (21) in the following pdf file?
In the first step several changes of variables are done to obtain the system (20),
then changes the variables again repeated in the neighborhood (w1 *, w2 *) to gain Eq 21.
I have 3 questuin:
1-The change of variables performed in the neighborhood (w1 *, w2 *)
for system (20) or for system (7) ???
2-What does it mean in the neighborhood (w1 *, w2 *)?
3- How did obtaun Eq (21)?

[upload link replaced by moderator, as violation of Term of Use]

[paperhub.ir]10.1016@j.neucom.2010.06.023.pdf

Could you please help me at the solution of my problem?

Let us consider the following list:

A := [x[1, 1]*(a*x[1, 1] + E[1, 1]) + x[2, 1]*(a*x[1, 2] + E[1, 2]) + x[3, 1]*(a*x[1, 3] + E[1, 3]), x[1, 2]*(a*x[1, 1] + E[1, 1]) + x[2, 2]*(a*x[1, 2] + E[1, 2]) + x[3, 2]*(a*x[1, 3] + E[1, 3]), x[1, 3]*(a*x[1, 1] + E[1, 1]) + x[2, 3]*(a*x[1, 2] + E[1, 2]) + x[3, 3]*(a*x[1, 3] + E[1, 3]), x[1, 1]*(a*x[2, 1] + E[2, 1]) + x[2, 1]*(a*x[2, 2] + E[2, 2]) + x[3, 1]*(a*x[2, 3] + E[2, 3]), x[1, 2]*(a*x[2, 1] + E[2, 1]) + x[2, 2]*(a*x[2, 2] + E[2, 2]) + x[3, 2]*(a*x[2, 3] + E[2, 3]), x[1, 3]*(a*x[2, 1] + E[2, 1]) + x[2, 3]*(a*x[2, 2] + E[2, 2]) + x[3, 3]*(a*x[2, 3] + E[2, 3]), x[1, 1]*(a*x[3, 1] + E[3, 1]) + x[2, 1]*(a*x[3, 2] + E[3, 2]) + x[3, 1]*(a*x[3, 3] + E[3, 3]), x[1, 2]*(a*x[3, 1] + E[3, 1]) + x[2, 2]*(a*x[3, 2] + E[3, 2]) + x[3, 2]*(a*x[3, 3] + E[3, 3]), x[1, 3]*(a*x[3, 1] + E[3, 1]) + x[2, 3]*(a*x[3, 2] + E[3, 2]) + x[3, 3]*(a*x[3, 3] + E[3, 3])]

I want to subs E[k,k]=1 when there is "a*x[k,k]+E[k,k]" as a part of polynomial in the above list.

Thank you so much in advance

In the following Solution_3.3_page_103.mw, after equation (15), I would like to use the clickable functionality to obtain the equations A, B, C, and D. I had to manually use copy-paste to obtain those equations. Because when I used the equation manipulator to square both sides, it started to be a mess.  After that, I was able to continue for (16) and the rest to obtain finally the speed of the muon neutrino.

P.S. If you see something wrong in the calculation, I am always interested to correct them.

Thank you in advance.

Hi,

I was able to get Procedure 2 to work using a for - do loop. I was wondering if it is possible to speed up the calculation by using map to find the number of roots? I do not fully understand map and passing data.

tgf := proc(a, b, c, d, t, m, n)

          local X;

          X := [solve(abs(a*x + b) + abs(c*x + d) - t*x^2 + m*x - n = 0)]; 

          return nops(X);

end proc;

res := CodeTools:-Usage(map(tgf, L));
Error, (in CodeTools:-Usage) invalid input: tgf uses a 2nd argument, b, which is missing

The L Array is tripping me up, here is a partial display of the array:

Array(1..262, 1..7, [[5,2,3,9,1,1,1],[5,2,3,9,2,1,1],[5,4,3,7,1,1,1],[5,4,3,7,2,1,1],[5,5,3,6,1,1,1],[5,5,3,6,2,1,1],[5,5,4,8,1,1,2],[5,5,4,8,2,1,2], ... ,[10,10,5,10,2,2,2]], datatype = integer[4]).

I made L Array into a list of list, R. Somewhat works.

Here is the script:

Roots_with_map.mw 

Thanks for any help.

Hi. is there a site for using maple online?

How to solve this integral equation?

rho:=1/(2);

mu:=1/(2);

T:=1/(4)*(t-x)^(1/(2));

E[rho,mu](T):=Sum((T^(k))/(GAMMA(k*rho+ mu)),k=0..5);
                       
eq1 := h(t) = (8/3)*(int((t-x)^(1/2)*E[rho, mu](T)*(1/(sqrt(Pi)*x^(1/2))-(3/32)*x^2+(3/16)*exp(-x)-1), t = -1 .. 1));       

 

Download 1.mw

Hi.

I have 7 polynomials r[9], r[6, 6], r[7, 9], r[8, 6], r[9, 6], r[6, 9, 7], r[6, 9, 6] each of 7 variables a[3],...,a[9] and I generate an ideal QQ usinig these polynomials. What Maple tells me quite fast is the follows:

IdealMembership(a[3], QQ) 

true

Also using Groebner as follows
F := [r[9], r[6, 6], r[7, 9], r[8, 6], r[9, 6], r[6, 9, 7], r[6, 9, 6]];
G := Basis(F, tdeg(a[3], a[4], a[5], a[6], a[7], a[8], a[9]));
provides me with the basis quite fast and a[3] is part of it. 

---------------

However, Mathematica is stuck and I have noticed that if I change a[3],...,a[9] to x,y,z,,v,w,t then Maple with the same polynomials is evaluating very long time. 

My question is: what am I doing wrong with subscripts a[3],...,a[9] in Maple? Does Maple 2019 have a problem with it?

I have attached my worksheet. 
Maple_Problem.mw
Would appreciate any help.

BRINKMAN_TRIAL.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/BRINKMAN_TRIAL.mw .
 

Download BRINKMAN_TRIAL.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/BRINKMAN_TRIAL.mw .
 

Download BRINKMAN_TRIAL.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/BRINKMAN_TRIAL.mw .
 

Download BRINKMAN_TRIAL.mw

hi, can anyone help me?

i am trying to solve a set of boundary layer equation.  when i executed the file, the following message appear.

Suppose I specify a metric in say the differential geometry package or Physics package that has an arbitary function f(x,y) of some of the coordinates as a component. Can I specify Maple to treat the function as real valued when Maple is asked to compute curvature etc for the metric? In some examples I have performed Maple sometimes returns expressions in f(x,y) for components that are in fact zero once one treats f(x,y) as real valued. It would be preferable to have Maple actually return '0' in such cases.

I tried the 'assume' command but Maple complained it was being applied to a protected name and I tried using

use RealDomain in simplify (5) end use

after Maple's computations, where (5) lablled Maple's output, but Maple didn't perform any simplification.

Hi, see above image, how do I get maple to do the chain rule automatically, for example, if I simply put in the alias V(h), instead of V(h(x)), this last command generates zero. 

Also, what is D(V)(h) ? is this equivalent to dV/dh, and if so how would I get maple to present it in this form?

Many thanks for your help ! 

I am using code edit region for parameters but getting this error, can someone help me to solve this issue.